Q.1. A quantity measured to be -30 m/s. Is it speed or velocity? Give a reason in your favour.

Asked by sbidipak | 30th May, 2017, 04:04: PM

Expert Answer:

  • The basic difference between Speed and Velocity is that the speed is a scalar quantity whereas velocity is a vector quantity.
  • In simpler words, velocity is a speed with the direction and at the other hand, the speed has no element of direction of motion involved in its expression.
  • Therefore, if the quantity is measured or expressed as '-30 m/s', then the negative symbol is an indicator of a motion which is opposite to the direction of the force applied.
  • With the element of direction in its expression, it can be concluded that the above quantity is an expression velocity and not the speed.

Answered by Abhijeet Mishra | 30th May, 2017, 05:40: PM